Alexandrite has its name from the Russian tsar Alexander II (1818-1881). The first alexandrite crystals were found in 1834 in emerald mines near the Tokovaya River in the Urals. It happened that this discovery came on the same day that the future tsar came of age. In the history of gems, alexandrite is relatively young gemstone, but it too has an interesting history. Its uniqueness lies in its ability to appear either red, or green, and sometimes with touches of both. Red and green were the main colors of old Imperial Russia, so it wasn't a stretch for the alexandrite to be named the national stone of tsarist Russia.
Today, natural alexandrite of good quality is extremely rare and almost never used in jewelry. It can, however, be found, albeit with difficulty, in antique Russian jewelry. Under the guidance of master gemologist George Frederick Kunz (1856-1932), Tiffany's produced a series of rings and platinum ensembles at the end of the 19th and beginning of the 20th century and, occasionally, one can find a Victorian piece of jewelry with alexandrite in it.
Alexandrite is basically colorless, or yellow transparent chrysoberyl. It contains iron and titanium, but also chromium as a major impurity. It is the chromium that in the daylight makes alexandrite appears green or blue-green, while indoors in incandescent light, it takes on a soft shade of red, purplish-red or raspberry red. This unique quality combined with its rarity makes it one of the valuable gemstones. The better the color changes, the more valuable the stone. Finely faceted stones over a carat are rarer than fine ruby, sapphire or emerald.
Russia remained the primary source of alexandrite until 1987 when alexandrite was found in Hematita, Minas Gerais, Brazil. Brazilian alexandrite showed color change that was not quite as good as its Russian counterparts. Brazilian clarity was quite good. Hematita remains a major source today. Some alexandrite comes from Sri Lanka, but unfortunately the hue of stones from there are not as good as those from the Urals. In the daylight they appear brownish and indoors they take on a brownish red color. In the mid-1990s, alexandrite was found in the Tunduru area of southern Tanzania, the quality of which was excellent. Alexandrite has also been found in India, Burma, Madagascar and Zimbabwe.
Today, most alexandrite is synthetic (i.e., lab-created). These stones have the same chemical and physical properties as natural alexandrite. Even their density and refractive index are the same and so they are very difficult to tell apart from natural alexandrite, except in price. A gemologist, or jeweler can use magnification to determine whether a stone is natural, or not. Every reputable jeweler will tell you if the stone is a synthetic. The good news is that because the natural and synthetic so closely copy one another, alexandrite jewelry is made available to a larger number of jewelry lovers.